Multiple centrifuge



Feb. 7, 1933. s. c. LINDBERG MULTIPLE CEN'IRIFUGE Filed March 7, 1930 liar/win portion of Figure 1, parts being broken away Patented Feb. 7, 1933' UNITED STATES;

PATENT OFFICE.

EVEN G. LINDBERG, NEW YORK, N. Y., ASSIGNOB, BY MESNE ASSIGNMENTS, TO GENTRIFUGAL ENGINEERING AND PATENTS CORPORATION, OF NEW YORK, N. Y., A

CORPORATION 0! NEW JERSEY I'ULTIPLE CEN'l'RIFUGE Application fled larch 7, 1930. Serial No. 438,886.

This invention relates to mechanism for purifying liquids by centrifugal action. The invention applies more particularly to liquids of the nature of aqueous cellulosic suspensions, especially suspensions of wood pulp such as are used in the manufacture of paper and the like. It is highly important in the manufacture of paper, particularly paper of the better grades, that the pulp be free from foreign matter such as specks of grit, 'rub-' her or other material which is not desired in the finished paper.

It is an object of the invention to provide apparatus which is capable of purifying efficiently a stream of wood pulp suspension or the like, the apparatus being characterized by strength and compactness of structure, economy of floor space required, and arrangement of parts to facilitate cleaning after a run. To this end I may mount on a shaft one or more multiple drums. Each of these drums may consist of a. pair of coaxial nested drums having walls radially s aced from-each other and having. a central not only separates the operative portion of the interior of the drums, but also reinforces and strengthens the structure.

I Various other advantageous features of construction will be apparent to one skilled in the art from'the description of the invention which follows and from the drawing, of

. which,:

' Figure 1 is an end elevation of apparatus embodying the invention.

Figure 2 is a side elevation of a couple of drums mounted'on a common shaft, one of Figure 4 is a fragmentary elevation of a to, show the arrangement of the members.

Referring to the drawing in detail, an embodiment of the invention may comprisea multiple drum consisting of an outer shell 10 and an inner shell 11, both of which may be mounted on and supported by a central frame ividing flange which on a shaft 12..

13 which, as shown in Figure '2, may conveniiently have an I-section. This annular member may be supported, as by a pair of ribs M'Which-extend to a pair of hubs 15, the latter being secured directly to the shaft 12.

The structure illustrated is designed to maintion. The outer drum is open at both ends and isprovided at each end with an inturned flan e 16. The inner drum-11 is spaced inwar 1y from the. outer drum and is secured to the annular member 13, as by an annular nemberl'? which includes inwardly extending flanges- 18 and is provided with suitable openings 19; At the ends of the drum 11 are flanges which extend inwardly at 20 to a greater extent than the flan s 18, and extend outwardly as'at 21. The provided with bent rims 22, as shown.

It is obvious that if a liquid suchas pulp stock be introduced into either of the drums during the rotation thereof at. a suitable speed, the liquid will form a cylindrical pool, under the actionof centrifugal-force of rotation, against the cylindrical wall of the drum. Thus, if pulp. stock be introduced into the inner drum, a pool will be maintained between the inward flanges 18 and 20 on each side of the supporting member 13. the drum wall than does the flange 18, a continuous addition. of pulp stock to this pool will cause the pool to overflow the flange 18 through the openings 19 and against the wall of the outer-drum 10 where an outer pool is thereupon formed; The action of the centrifugal force of rotation not only maintains these pools against the cylindrical walls of the drums, but also tends to cause particles of foreign matter having a density greater than that of pulp to move radially outward nearer to the adjacent wall of the drums, the im urities of lesser density than that of the pu p tending to float on the surface of the pools.

When the operationof the drum is started, the first pulp forms a loose mat of fiber anges 21 may be against the walls of the drums, the fibers in this mat exerting a combing action on the stream of pulp which flows over them, this combing action tending to entrap and hold the heavier particles of foreign matter which may be in the pulp stream. The light particles flow with the stream through the openings 19, but may be caught behind the flanges 21 if the outer pool is maintained at a sufiicient depth to submerge a portion of this flange, including the bent rim 22. The drum may be supplied with puip stock, as by' a suitable supply pipe 25 from which branch pipes 26 lead to within the opposite ends of the inner drum 11. The open end 27 of each pipe 26 may be turned in the direction of rotation of the drum so as to facilitate the introduction of the streaminto the pools within the drum 11 with the least disturbance, and consumption of power. As the fresh stock is supplied adjacent to the outer ends of the drum 11, the stock in these pools is displaced toward the center of the drum where it overflows through the'openings 19 into the pools in the drum 10. This displaces the pulp in these pools toward the ends of the drum 10.

In order to remove the purified pulp a pair of scoops 30 may be provided for each drum, these scoops entering the opposite ends of the drum and being adjustably attached to discharge pipes 31, as indicated in Figure 4. By adjusting the scoop 30 so that its clearance from the wall of the drum 10 is varied, the depth of the pools within the drum 10 may thus be regulated. The discharge pipes 31 may be connected with a common dis charge pipe 32 by which the purified pulp is removed to any desired point. b

As shown in Figure 2, the drums may be mounted on a horizontal shaft 12 which is supported by suitable bearing members 35,

thus be mounted on a common shaft so as to drums, one within the other, common means supporting said drums at their median plane, said supporting means including a partition member extending from the outer drum radially inward beyond the wall of the inner drum, inwardly extending flanges at both ends of said drums, said supporting means having openings therein connecting the inner and outer drums at points spaced radially inwardly from the wall of the inner drum, means for supplying liquid to be purified within the inner drum at points adjacent to the opposite ends thereof, means for removing the purified liquid from the outer drum at points adjacent to the ends thereof,

and means for rotating said drums.

2. A centrifuge for purifying liquid, comprising apair of coaxial nested drums, a central member supporting bothsaid drums, supply means for introducing liquid to be purified into the inner drum adjacent to the ends thereof, means for removing purified liquid from the outer drum adjacent to the ends thereof, said drums being constructed to cause liquid introduced through said supply means to flow in streams toward the center of the inner drum and from the center of the outer drum toward the ends thereof, and means for rotating the drums, I

3. Centrifuges for purifying liquids, com prising a pair of concentric nested drums having walls mutually spaced from each other, supply means for introducing liquids to be purified into the inner drum adjacent to the ends thereof, inwardly extending flanges on saidvinner drum adapted to maintain a pair of pools of liquid therein, the flanges adjacent to the median plane of the drum being narrower than the flanges adjacent to the ends of the inner drum, where-' by the pools in said inner drum overflow into the outer drum at points adjacent to the median plane thereof, means for scooping purified liquid from the outer drum at points adjacent the ends thereof, said scooping means being adjustable toward and from the wall of the outer drum, outwardly extending flanges on the inner drum adjacent the ends thereof, and means for rotating said drums.

4. A centrifuge comprising a drum open at both ends, a shaft coaxial with said drum, bearings for said shaft adjacent to the ends of the drum, a supporting frame secured to said drum in its median plane only, said frame having a pair of hub elements mounted on said shaft and spaced axially from said plane, each said hub element being substantially as near to the adjacent shaft bearing as to the other hub element.

5. A centrifuge comprising a horizontal shaft, a drum open at both ends mounted on said shaft for rotation therewith, means for supporting said drum on said shaft, said supporting means engaging the drum in its median plane andhaving hub elements on said shaft substantially spaced axially from said median plane, and a pair of bearings for said shaft adjacent to the ends of said drum. 7

6. A centrifuge comprising a rotatable shaft, an annular ring around said shaft and spaced therefrom, means including a pair of hub members on said shaft substantially spaced from the plane of said ring for sup porting said ring for rotation with said shaft, a pair of nested drums coaxial with said shaft and mounted on said ring at their median planes, said ring forming a central partition within said drum, said drums each being open at both ends, inturned flanges at said open ends, means for supplying liquid to the inner drum adjacent to both its ends, and means for removing liquid from the outer drum at points adjacent to both ends thereof.

7. A centrifuge comprising a pair of nested drums each open at both ends, a shaft coaxial with said drums, means on said shaft for supporting said drums at their median planes, said supporting means including a partition member extending inwardly from.

the shell of the outer drum, inward flanges at both ends of both drums, outward flanges at both ends of the inner drum having outer edges spaced inwardly from the outer drum, means for feeding liquid to be purified into said inner drum at points adjacent to the ends thereof, and means for collecting and leading off the purified liquid adjacent to the ends of the outer drum;

In testimony whereof I have aflixed my signature.

SVEN C. LINDBERG. I v 

